Improvement in production and treatment of resin



A. ROCK.

PRODUCTION 'AND'TREATMENT'-0F RESIN.

No179,960. Patented J'111y18,187"6 y gathered.

ADOLPHE ROOK, OF NEW ORLEANS, LOUISIANA, ASSIGNOR OF ONE-HALF HIS RIGHT TO EDWARD VORSTER, OF SAME PLAGE.

IMPROVEMENT IN PRODUCTION AND TREATMENT oF RESIN.

Specification forming part of Letters Patent No. 179,960, dated July 18, 1876; application tiled November 17, 1875.

To all whom it may concern:

Be itknown that I, ADoLrHn ROOK, ot

.New Orleans, parish ot' Orleans, and State of Louisiana, have invented a certain new and useful Process ofDistillimgy Turpentine, Manufacturing and Treating Resin, and Apparatus therefor; and I do lhereby declare that the following specification, taken in connection with the drawings furnished and forming a part of the same, is a clear, true, and complete description thereof.-

- lt is well known that in the art of distilling turpentine no appara-tus is now considered ashavingpractical value which, while effecting a complete and perfect distillation, performs that service without maintaining' in the biproduct, or resin of commerce, those characteristics which are deemed of value to the consumer.

ln the mercantile classification of nava stores, as generally accepted in the trade, resin is sampled in twelve grades, rangingin alphabetieal order, (omittiugvJ and L) from A,77

This latteris the ond, Virgin Scrap, which follows the dip, and is a similar' exudation from the same new trees during the first year, solidified by cxposure; third, Old Dip, which is taken from the frees after the first year, before referred to, and which i'lows for a short time in the spring of cach year, fourth, Old Scrap,y

which is scraped from .the old trees during the balancent' the year, after t-he old dip has been Under some circumstances, with apparatus heretofore in use, by the exercise of great care and skill, it has been possible to produce the high grades of resin from the virgin dip been insufficient to meet it, and, therefore, L

resins of low grade are shipped abroad, there treated under various refining and bleachfing processes, and in the form of highgrades are reshipped to this country to find a ready and profitable market.'

These retiningand bleaching processes involve the extensive use of alcohol and ether, which, being much cheaper abroad than in lthe United States, places the foreign refiners beyond the reach of domestic competition.

There is still another class of resins, sometimes called boiled resins, which are neither y black nor transparent, but are light-coloredand opaque. 4This class has no grade in the market, but is usually sold at same rates kas B and C of the regular grade. These resins contain water, and are the vproduct of distilling operations, Which-involve the use of water or direct steam in considerable quantities, in contact with the crude turpeutine. So far as my knowledge extends, prior to my invention resin of this class could not be freed from its water and produced in high grades except by the refining processes before referred to, involving the use of alcohol and ether. It has, however, with apparatus heretofore employed, been freed from water and produced in very low grades, seldom` it' ever higher than D -or E.

Chemists .have clearly demonstrated that pine resins derive their color from the presence of colopholic acid, and also that this acid is more or less developed in resin, according to the degree of heat to which the resin may have been subjected, and the period of its exposure thereto. d

I have practically deI'uonstrated that resin of grade N, if subjected to heat at about 1850 Fahrenheit'for about four hours, will fall in grade to I, which is next below K, or Low Pale, and this depressionis wholly owing to f posed thereto, a high degree of heat may be` safely employed, and that by intermittent exposure the volatile vapors may be wholly eliminated without developing' the coloring-` acid.`

Unless the volatile spirits are whollyexpelled good resin cannot be produced. 'lhese spirits are readily evolved at a temperature which Will thoroughly melt the crude turpentine. At the melting-point, however, colopholic acid will be developed, provided the melted matter belong exposed to the meltingtemperature; and it is, therefore, importan-t that the distillingi operatioube performed by an intermittent exposure of the turpentine to a melting-heat, which has, as I believe, never been done prior to my invention.

.The prime object of my invention is to produce a high grade ofthe bi-produot, or resin, without any depreciation ot' spirits, either as to quality or quanti-ty.

'lhe main feature of my invention is an improvement in the artof distilling scrap-tur pentine and producing rofsiu therefrom, which consists in the elimination of the condensable' vapors froml the scrap-turpentine treated in the retort 'during distinct and separate meltings or .exposures of said matter to a meltingheat, succeeded in each instance byan exposure thereotl to a cooler temperature, and in condensing the vapors, whereby the distillate is secured, and also whereby colopholic acid isprevented from being unduly developed in therosin.

I- have already explained that if the turpentine or the resin` be subjected even to a 4melting-temperature for anyconsiderable periodthe coloring-acid Willbe developed. In the pre-existing methods or processes relating to this art know'n to lne, the crude scrap-turpentine is either melted prior to its introduction to the retort, or, by an older method, introduced in cold mass before the retort is heated. In bot-h of these methods the melting-point is necessarily maintained for a period of time, which inevitably results in the development otan objectionable quantity of colopholic acid, and a consequent discoloration ot' the biproduct. By means of this, the main feature ot' my invention, the condensable vapors are eliminated while the matter is melted, and the undue development of colopholic acid prevented, because the matter is immediately thereafter `exposed to a cooler temperature.

Another feature otl my invention is an improvement in the'art of distilling dip-turpen- ,tine and manufacturing rosin, which consists in the elimination ot' the condensable vapors from the dip-turpentine during the introduction of the dip into the retort in ne streams the distillation of crude dip-turpentine and the A production ot rosin, the dip was ever heretofore introduced into the retort iu jets or in the y form of spray during the injection of forced currents ot' air into the retort for conveying the vapors to the condenser.

Another feature of my invention is an 1m'- ,provement in the manufacture of rosin from poor scrap-turpeutine, and in the treatment of boiled rosin, which consists in eliminating the aqueous and other vapors from said turpentine or rosin `by means ot' currents of air sweeping over the turpentiue or rosin whil'fsuccessively melted and cooled, whereby no portion of the rosiu or turpentine is unduly-heated,

and the undue development of colopholic acid i prevented. t

I am aware that it was proposed by one Williams, as set forth in English Patent No. 7,770, A. D. 18,38, entitled For purifying turpentine, resin, pitch,77 85e., to 'drive from bitumen, and from other matters mentioned in the title of said patent, ammoniaca-l gas,

and other gases known to be injurious in the process of burning for the production of light and heat,77 by means of currents of atmospheric air brought into intimate contact with the bitumenwhile heated at or near the boiling-pointJ in apan, and during the alternate lifting of portions ot'.said matter. in a perforated pan or colander, audits discharge therefrom back to the pan. This process, as proposed by Williams, if applied to crude turpentine or rosin, would defeat the very object sought by me, in that the turpentine or resin would, of necessity, be vheated far above the melting-point, in order that it should have the requisite degree of fluidity to admitthe use of the eolanders. Moreover, the contents of the pan would, ot' necessity, have to be kept very hot, and at nearly the boilin g-poin t, tor a considerable length ottime, in order that all the contents might be operated upon by repeatto discharge into the pan.

edly llliug the cola-nder and lifting it, so as i I am also well aware that one .Latt'a-rge, as i described in his French Letters Patent of May 14, 1855, proposed to use warm air for the manufacture of turpentine fromresinous substances, or, more properlyspeaking, for the perfect purification of spirits of turpentine Without loss, and that he proposed toeniploy for the purpose a chamber containing a sieve or lilterer, a hot-air furnace, provided with air-heating pipes, over 4Which atmos- 179,960 l i s plierie air passed, which, when heated, entered said chamber, and was laterally diffused by means of a deiecting-plate extended across the opening or air-entrance. Laiarge employed, also, an air-valve at an' exit-aperture in the chamber, so adjusted as to maintain the hot air within the chamber at a uniform pressure. From the fact that Latfarge employed the delecti-ng-plate in front ofthe air-entrance, and between it andthe sieve, for directing the incoming air laterally and vertically, and the fact that he had his airexit guarded by a valve which only opened when a certain degree of pressure was 'attained in the chamber, and also from the fact that no pressure could be attained greater than that incident to the expansion of atmospheric air by the heat imparted thereto by the heating pipes of the fur-- apparatus, no valuable results could accruer through the intermittent heating` and cooling` of the iiuids. O n the contrary, a uniform temperature is preferable in all processes which are simply evaporative, wlule, 1n accordance" with my invention, the intermittent heating and cooling ofthe crude turpentine and rosin prevents the injurious development of the colopholic acid.

I have already explained that when resin contains water it is called boiled resin,77 is light-colored, opaque, has no specific grade in the market, and sells at a comparatively low price, and that, prior to my invention, it had never been so treated as to improve it to a high grade, except by refining-processes involving the use of alcohol and ether. Under Vthis last-stated feature of my invention such resin may be deprived of its water, because when it is melted the water rises to the surface, is evaporated by the hot-air blast, and driven from the retort.

The dip-turpentine owes its iiuidity to the presence of the volatile spirit in large quantities; but itv also contains a considerable quantity of water. 'Ihe water, to whatever extent it exists, or whatever proportion it may bear to the turpentine, if retained in the resin, depreciates its value; for driving it off by direct. contact with heat requires a temperature which unduly develops the colopholie acid. By the employment of an air-blast, at

a temperature always preferably lower than melting-point, the Water from the dip'is taken up by evapora-tion and driven from the retort.

It is not new either to treat turpentine in retorts by means ot' radiating heat, or without the employment of water or steam in direct contact with the turpentine, but in all previous instances known to me, the condensable vapors are driven from such retorts purely by the expansion of' those vapors incident to the effect of the heat applied thereto, and therefore, if the watery vapors are eliminated at all, it requires a high degree of heat, instead of the low heat .of the air-blast and its evaporative action, as under my process.

I am aware, however, that it has heretofore l been proposed to employ an exhaust air-pump in connection with a retort and condenser in the distillation of turpentine, for the purpose o f distilling under what is'termed the"vacnum process,77 and that by these means the operation could be conducted with a lower degree of heat in the retort than by the usua methods generally practiced.

In connection with the treatment of petroleum-oils,'for depriving them of more or less of the volatile matters contained therein, I am aware that a high-temperature air-blast has been heretofore proposed forv sweeping over the surface of the oil in the retort, and eliminating the volatile matters therefrom and driving them from the retort; but I am not aware that such a blast has ever been proposed in connection' with the distillation ot' turpentine prior to my invention, or that an apparatus was evermade for operating on petroleum or other oils which would be capable of operating on turpentine without embodying in thefretort features in construction and arrangementA which constitute portions of my present invention.

There is a class of old trees which yield, crude turpentine so deficient in volatile matter that it will 1'|ot' pay to worll it for the spirits it would yield, nor with any pre-eXist-' ing apparatus known to mc can resin be made therefrom, except. of the lowest grades, and

therefore attempts to utilize it are seldommade. Under that portion of my invention last stated, resins ofthe higher grades may be profitably made from such turpentine, even if the condensable vapors be allowed to escape vinto'the open` air, instead of being conveyed to the condenser.

That portion of my invention which relates to the apparatus consists,'tirst, in a retort for distilling turpentine, the combination of one or more 'skeletouized shelves, a dischargingapron below the shelves, and feeding-apertures provided with suitable covers, located in the shell of the retort adjacent to the shelves,

whereby crude scrap-turpcn'tine may be fed to the retort by placing it on said shelves, and

alsowherebythe turpentine, as itis melted, may drip from one shelf to another, or to the apron,land during its descent be favorably exposed for parting with its volatile'vapors 5 whichsecond, in a retort for distillin g tu'rpentiue,l a dischargiiig-apron and-one or more skeletonized shelves, provided witlrinternal heating ues or passages, in combination with air-induction passages and vaporeduetion passages, whereby aeriform currents, more or less heated, may be directed through the retort, over and between the shelves, and over `the discharging-apron, thereby eliminating the condensable vapors from Ythe :turpentine on said she] ves, and falling` therefrom and driving them to a condenser; third, in combinationwith a retort for distilling turpentinc, a skeletonized shelf, provided with interior heating-passages and a cloth lterer, whereby the crudeturpentine is .thoroughly iltered while in the retort during` theelimination of its condens-able vapors; `fourth, the combination of one or more skeletonized` shelves, provided with interior heating-passages and a ilterer, a discharging-apron, and air-passages over and under the shelves, and over `the apron, whereby old scrap-turpentine, containing but little volatilesmatter, `may be made into resin of high grade.

To more particularlydescribe my invention I will refer4 to the accompanying drawings, in

`Figure l represents, in perspective, an appamtusembodying `the several features of my invention. Fig. 2 represents the same in longitudinal vertical central section.

As my invention relates to the treatment of the turpentine and resin in the retort, I have not shown any condenser, and it will be understood that anysuitable condensing apparatus may be employed therewith.v Norhave I shown steam-boilers, fans, or air-heating apparatus, as such devices are well known, and may be readily and favorably selected by persons skilled in Vsuch matters.

My retort is shown at A, Its form may be varied; but I prefer that it be rectangular and box-like, as shown. It is preferably mainly constructed ofwood, with or without a copper lining. Inasmuch as the resin is liable to .injury fromeontact with iron, I prefer to use noue of that metal in its construction, except it be coated with copper. The retort is provided at its top with close-fitting covers, as at a, which may be removed for introducing the matter `to be treated. These covers should have seats, provided with a suitable packing for securing good joints. For convenience, I prefer that the retort should be so set that barrels may be placed beneath the dischargeaperture,` as at b, for receiving the resin.

In order that free access may be had to the interior ot' the retort, l provide side openings with covers, as at c.

B denotes a skeletonized shelf, located within theretort, and extending from end to endv and side to side. I prefer to construct itof numerouscopper pipes, d, placed side by side, extending from one end of the retort to the other end, and back again in nearly the same` ally fromits rear surface.

plane, and'communicating with larger pipes, as at dl and d2, one of which is' connected with a steam pipe and boiler, and through the other, as at d1, the waters of condensation areV show but one, as at e,inconnectiou with the uppershelt'. So, also, may each shelf be provided with a cloth filterer, although'I show but one, `as at f,'on thelower shelf. This iilterer is,

preferably, composed of coarse cotton cloth,

and is susceptible of retaining all those'motes, Ste., which should` nevel' be lfound in wellstrained resin. l

C denotes the discharging-apron.` 'It isloeated at the bottom of the retort, is concave from side to side, and inclined downward from one end of the retort toward the dischargeaperture for the resin, as at b. Beneath the discharging-apron, and closely adjacent to its under surface, there is a steam-pipe extending longitudinally to and' fro, whereby the apron .may be kept a-t a desirable degree of heat.

-The discharge-aperture b is partially circular, and is guarded by a plate, as atg, which has a circular ange, as ath, extending later- The lower part ot' the adjacentend of the apron is curved, so as -to receive the iiaugeand ati'ord a joint suiii-` cient-ly close to prevent the escape ofthe soft resin. The plate y is provided with a tubular spout, which may be closed, when desirable,1 by means of a plut. Y

I), in each instance, denotes one of three air-induction passages. Theyare located at one end ofthe retort, and communicate with: the interior thereof by means of suitable open ports. 'Ihree of these passages are4 shown. The upper one delivers air into `the retort above the upper shelf, the middle one between. the two shelves, and the lower-one between the lower shelf and the dischargingapron. These passages are connected with a pipe, from which they receive aeriform currents. These passages are `connected with a supply iiue o'rpipe, through which heated air may be driven by means ot' any suitable forcing apparatus. Each ot'these passages should be provided with a valve or cock, wherebythe quantity of air admitted to the retort may be varied or cut off entirely to meet special requirenlents.

E, in each instance, denotes one of three vaporeduction passages. Theyare located at the end oftheretort oppositefto the air-induction-passages, and are arranged in like manner with reference to the shelves and apron. The ports in `these passages, vwhich Waeco' l 5 I communicate with the interior of the retort,

should have a somewhat larger aggregate of.

area than that of the air-induction ports. These several vapor-eduction passages are connected with a pipe, which conveys the vapors to a suitable condenser. (Not shown.)

F denotes a receiver for dip-turpentine. It

is box-like in form, and has at its bottoni a passages, so that the turpentine may be injected into the retort through the jet-pipein iine streams or spray. rIhe pipe a may, instead of containing a blast of air, be connected with a steam-boiler, and, by means of steam, effect the same purpose without endangering the resin by reason of the water of condensation, as will hereafter be fully described.

The strainer in the receiver is -merely to prevent bulky extraneous matter from entering and clogging up the jet-pipe. The coil need only be used when the dip requires heat with a view to giving greater' fluidity.

Instead of using the blast of steam or air for effecting the injection of the dip into the retort, a pump may be employed, which, operating directly upon the dip, will force it continuously or intermittently through the jet-pipe.

Having thus described a desirable form of apparatus in detail, I will say that the dimensions will be varied to meet requirements. The spaces between the shelves and above the apron may be varied from, say, six inches upward, and effectdesirable results.

In explaining operations with such an apparatus I can only refer to the several general conditions under which it would, in practice, be operated.

In practice the quantity of scrap-turpentine to be treated largely exceeds the quantity of dip, and I will, therefore, iirst describe operations with the scrap.

- For scrapdistillation but one wire straineris used in the retort, and that is on the upper shelf. A single cloth filterer is used, which is located on thelower shelf. In charging the retort the upper covers a are removed, and the upper shelf loaded with scrap to a depth preferably ranging, say, from six to twelve inches. Ihe covers are then replaced, and the steam let into the pipes composing the shelves. The heat attained on these pipes need seldom, if ever, range higher than 1850 Fahrenheit. The scrap in contact therewith melts and falls to the lower shelf upon the cloth ilterer. The air-passages are opened,

so that the currents will pass from one end of the retort to the other, above and below the shelves, carrying into the eduction-apertures the condensable vapors.' 'The air thus intro-v duced need seldombe of a ltemperature above 11500 Fahrenheit. As the tnrpentine melts on the upper .shelf the watery portions naturally rise to the top of the melted mass, or to the surfaces of the lumps, and are evaporated and carried to the condenser with the spiritnous :vaporsn There is an extensive evaporative surface afforded at the upper shelf to the up-v per current, and as the turpentine trickles yfrom one shelf to the other, and to the apron below, it is also favorably exposed 'for elimination of the spirituous matter.

The-cloth tilterer on the'second shelf so retards the passage of the melted matter vthat if water still be therein after passing the upper shelf, it

-will rise to the surface, and be evaporated byq the current of air which sweeps over-it.

It will be seen that theturpentine, leaving `the upper shelf at, say, 1850 Fahrenheit, in

passing to the lower shelf, is exposed to a cooler temperature, and that it reaches the lower shelf below the melting-point, is then raised to melting-point, passed through they tilterer'to the apron below, being cooled in its descent in like manner, andon the apron again raised to the melting-point, and discharged thoroughly freed from the volatile ,matters Acontained in the crude turpent-ine. ,At no period of the process need the heat be raised to a degree which will unduly develop the colopholic acid, nor is it long exposed at any one time to 'even that degree of heat req- Auisite to effect la favorable passage of the matter from shelf to shelf, and to the apron, and to eliminate all condensable vapors.

Under some circumstances, if the scrap be not over rich in spirituous matter, a sin gle cur rent of air may be relied upon for eliminating 4from the melted turpentine those matters, so

thoroughly is the turpentine exposed to the air in the retort. In this case the dischargeaperture may be wholly opened for delivering the resin to the barrels. It is not to be understood that the air-currents need be always artificially heated, for during warm dry days the prevailing atmosphere may be successfully employed.

' For operating on dip-turpentine the, apparatus isadjusted somewhat differently-that is'to say, instead of having va cloth lterer on one shelt'only, I use one on each shelf. Coarse unbleached cotton cloth is preferred,ot` the same character as has for several years been employed instraining the resin after it leaves the retort. pipe m, from the receiver F, into the retort above the upper shelf, and at its entrance is met by the current of air, which eliminatesy promptly a good proportion of the condensable vapors. rlhe fluid falling upon the lterer is there held collected in mass to a greater orlesser extent. As before stated,'the dip conn-l Thedip is forced through the jet-V tains much water, and this, rising to the surface, is taken up by the air, by a purely evaporative. process, and is carried to the condenser, Where it is separated from the oily spirits, as heretofore. In trickling from the upper iilterer to the one below, it is, as in the case of the scrap, exposed to a cooler temperature, then heated again on the lower shelf, and passes through its cloth iilterer. As described in connection with the upper iiltercr, this last one affords a surface ou which the remaining water is retained, which is evaporated as before. In falling to the apron below, it is again exposed to a current of air, cooled somewhat, and, on reaching the apron, is raised again in temperature until discharged therefrom. As the air is, in this case, employed between the apron and the lower shelf, it is desirable that lthe discharge-aperture be closed andthe resin 4 drawn oii from time to time through the pipe or spout in plate g. In this last case the apron holds the resin in considerable quantity, completely guarding the discharge aperture again-st the passage of vapors which should be conveyed to the condenser'.

It will be seen that I can safelyemploy steam for assisting in the injection of the dip through the jet-pipe, because the water ot' condensation is thoroughly evaporated by the air-currents, and .it cannot, therefore, injure the character ot the resin.

In operating on dip, I prefer not to heat the ripper shelf until a sufficient charge has been injected to, say, the depth of several inches onthe shelf.

.The cloth filterers are secured by tacking them to the sides and ends ofthe retort, or to a frame which snugly fits therein. So far as relates to the effectual separation of waterl'rom turpentine or resin, the cloth lterer performs an important service. It is clear that the water cannot freelypass through the cloth unless the latter be first saturated therewith.

Being melted and quiescent, the resin or tur,

pentine 'affords an opportunity for the water to rise to the surface, while the melted matter passes through the Iilterer. A small quantity of water will, however, pass with the melted matter through one iilterer, if not previously so exposed that it may partially be removed, as in the case of the upper shelf already described in connectionA with the operations with scrap-turpentine. If a heavy woolen fabric be employed, a single iilterer may in some cases be made to serve the purpose of two filterers composed of cotton cloth.

In treating that class of scrap which is too poor in spirit-nous matter to make it an object to preserve it, but having avalue for making resin, the retort may bedisconnected from the condenser, and the hot-air currents employed, so as to deliver the aqueous and other vapors directly into the open air 5 or, in dry, breezy weather, the artificially-induced currents may be dispensed with, the top and sides of the retort removed, and the surfaces lform this service by dow-ing thev resin in a melted condition (previously groundV and subvjected to the bleaching action ot' chemicals) into a retort, and in `so heating the melted matter as to drive oit' the water after iirst converting it into steam.- It'is clear that by this method a high degree of heat must be employed, at least to a degree which is required for converting the water into steam. Under this method no currents of air have been employed, and no circulation can be effected within the retort, and no air or vapor can leaveit, unless forced therefrom by the expansion incident to the heat employed. I treat such resin in my retort by exposing it on the upper shelf, after the manner of treating the scrap 5 but, as

it contains no spirituous matter ot' value, thef watery vapors are discharged into the open air.

It will be seen that at no time during the operation is the resin exposed to a higher degree of heat than is necessary to melt it and allow it to fall from shelf to shelf, and to the apron, and to flow therefrom. The currents of air perform strictly an evaporative service in disposing ofthe water, and, not having 4 been heated to a degree which could develop colopholic acid, and having been alternately heated and cooled in the retort and deprived of water, the product from the apron is-bright, transparent, and of. high grade. lterers in this connection, as assistants in the separation of the water from the resin, operate as before described. i

When the Weather is dry and breezy, the artificially-induced currents oi' air may be dis; pensed with by removing the top and side covers, and allowing a free circulation :of the atmosphere between the shelves, as has already been suggested ,in connection with poor scrap.

.It will be seen that I rely upon 'air asa vehicle for eliminating the condensable vapors,

both aqueous and spirituous, and that the function performed by the air is therefore purely mechanical; and although in some instances y it may be desirable to employ gases of a bleaching tendency instead of air, it is obvious that they would, nevertheless, serve as vehicles for A the elimination and conveyance of the condensable vapors, and so perform the same servgze in the operation which would be performed y air. r i It will also be seen that the construction of the retort may be largely varied without departing from the true spirit of my invention, and l therefore do not limit myself to any precise The cloth` construction and arrangement of the several portions of the apparatus.

I am a'ware that the shelves might be provided with steam-chambers, be made of short length, and inclined alternately in opposite directions, so that the turpentine tlowin g over the upper shelf will, falling therefrom to the next below, pass along that to the next shelf, and so on to the discharging-apron. In such case the shelves, being short, and having frequent breaks between them, would operate as skeletonized shelves, which are provided solely so that the melted matter, in falling from one shelf to another, may be favorably exposed for the elimination therefrom of the condensable vapors.

Having thus described my invention, I claim as newl. The novel method of distilling scrap turpentine and producing rosin therefrom, which consists in the elimination of condensable vapors from scrap-turpentine while treated in a retort during distinct and separate meltings or exposures thereof to a melting-heat, followed in each instance by an exposure toa cooler temperature, and in condensing the vapors, substantially as described, whereby the distillate is secured, and also whereby colopholic acid is preventedfrom being unduly developed in the rosin, as set forth.

2. The improvement in the art of dist-illing dip-turpentine and manufacturing rosimwhich consists in the elimination of condensable vapors from dip turpentine during its intermittent or continuous injection into a retortv inline streams or jets, or in the form of spray during the injection of forced air-currents for conveying the vapors to a condenser, substantially as described, whereby the distillate is secured, and also whereby the condensable vapors are eliminated at a low temperature, and the resinous residuum protected against thc undue development of eolopholic acid therein, as set forth. y 3. The improvement in the manufacture of rosin from poor scrap-turpentine and in the treatment'ot' boiled rosin, which consists in eliminating the aqueous and other vapors from said turpeutine or rosin by means of currents of air sweeping over the turpentine or rosin while successively melted and cooled, lsubstantially as described, whereby no portionof the rosin or turpentine is unduly heated, and the undue development of colopbolic acid prevented, as set forth.

4. In a retort for distilling turpentine, the combination of one or more skeletonized sl1elves,a discharging-apron below the shelves, and feeding-apertures, provided with suitable covers, located in the shell ot' the retort adjacent to the shelves, substantially as described.

5. In a retort for distilling turpentine, a discharging-apron, and one or more skeletonized shelves, provided with internal heating fines or passages, in combination with air-induc tion passa-ges and vapor-eduction passages, substantially as described.

6. rlhe combination, with a retort for distilling turpentine, of a skeletonized shelf within the retort, provided with interior heatingpassages and a cloth flterer, substantially as described.

7. rIhe'combination, with 011e or more skeletonized shelves, provided with interior heating-passages and a iilterer, of a dischargingapron, and air-passages over and under the shelves vand over the apron, substantially as described.

ADOLPHE ROCK.

Witnesses:

WM. G. Woon, PHILIP F. LARNER. 

